Fan noise at a certain RPM?

[Elixer]

This is a bit odd, on a EVGA 750, the fan makes a kind of a rattle noise only at a specific RPM, which is around 43%.
If it goes lower than 43% or higher than 45%, then no odd noise comes from the fan.
I thought it might need cleaning, but, there wasn't any dust on the fan worth mentioning.

Since it just started to happen, I am assuming that the bearings might be going bad?

 

[nerp]

If it never made the noise until recently, then yes, one of the bearings might be on its way out.

 

[sxr7171]

It may always have. Resonance is a possibility.